diff options
| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-07-24 12:51:10 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-07-24 12:51:10 -0400 |
| commit | dc05973b288a5226bb7e56afd6c2fa07560a907c (patch) | |
| tree | 2e1eade8b6010ff4c844341fdeec9ee966d75ac7 /drivers/usb/host/ehci-hub.c | |
| parent | 297fae4d0bee5d683533f3324baf1b363e7b48bf (diff) | |
| parent | e7bdea7750eb2a64aea4a08fa5c0a31719c8155d (diff) | |
Merge commit 'e7bdea7750eb'
Needed in order to work on top of pNFS changes in Linus' upstream kernel.
Diffstat (limited to 'drivers/usb/host/ehci-hub.c')
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index ffc90295a95f..74f62d68f013 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -872,15 +872,23 @@ int ehci_hub_control( ) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); int ports = HCS_N_PORTS (ehci->hcs_params); - u32 __iomem *status_reg = &ehci->regs->port_status[ - (wIndex & 0xff) - 1]; - u32 __iomem *hostpc_reg = &ehci->regs->hostpc[(wIndex & 0xff) - 1]; + u32 __iomem *status_reg, *hostpc_reg; u32 temp, temp1, status; unsigned long flags; int retval = 0; unsigned selector; /* + * Avoid underflow while calculating (wIndex & 0xff) - 1. + * The compiler might deduce that wIndex can never be 0 and then + * optimize away the tests for !wIndex below. + */ + temp = wIndex & 0xff; + temp -= (temp > 0); + status_reg = &ehci->regs->port_status[temp]; + hostpc_reg = &ehci->regs->hostpc[temp]; + + /* * FIXME: support SetPortFeatures USB_PORT_FEAT_INDICATOR. * HCS_INDICATOR may say we can change LEDs to off/amber/green. * (track current state ourselves) ... blink for diagnostics, |